It is convenient to use an optical circuit for control of machine tools in a factory environment in which there is a high background of electrical noise produced, for example, by the starting and stopping of many motors and other electrical background producing devices. Central to the use of an optical circuit for controlling machines in a factory is to have a convenient optical switch which may be used with fiber optic light conductors. One approach to an optical switch for use in the factory environment is shown in U.S. Pat. No. 4,223,217, issued to Bongard, et al. on Sept. 16, 1980. The Bongard, et al. reference shows a shutter mechanism for turning a fiber optic circuit "on" and "off"
The practical use of optical fiber circuits in a factory environment for controlling machine tools requires an easily utilized optical switch. The switch should be capable of both switching an optical circuit from "on" to "off", and simultaneously switching a second optical circuit from "off" to "on". To be useful, such an optical switch must be capable of convenient integration with common machine tool control devices such as push buttons limit switches, pressure responsive switches, and selector switches.